A laser beam machining method and a laser beam machining device capable of cutting a work without producing a fusing and a cracking out of a predetermined cutting line on the surface of the work, wherein a pulse laser beam is radiated on the predetermined cut line on the surface of the work under the conditions causing a multiple photon absorption and with a condensed point aligned to the inside of the work, and a modified area is formed inside the work along the predetermined determined cut line by moving the condensed point along the predetermined cut line, whereby the work can be cut with a rather small force by cracking the work along the predetermined cut line starting from the modified area and, because the pulse laser beam radiated is not almost absorbed onto the surface of the work, the surface is not fused even if the modified area is formed.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object to form a modified region caused by multiphoton absorption within the object, to form a starting point, from which cutting of the object starts, constituted by the modified region in a region separated from a surface of said object a laser light entrance face side toward inside by a predetermined distance along a line along which the object is intended to be cut.
2. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object to form a modified region including a crack region within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a starting point, from which cutting of the object starts, constituted by the modified region in a region separated from a surface of said object a laser light entrance face side toward inside by a predetermined distance, along a line along which the object is intended to be cut.
3. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object to form a modified region including a molten processed region within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a starting point, from which cutting of the object starts, constituted by the modified region in a region separated from a surface of said object a laser light entrance face side toward inside by a predetermined distance, along a line along which the object is intended to be cut.
4. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object to form a modified region including a refractive index change region which is a region with a changed refractive index within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a starting point, from which cutting of the object starts, constituted by the modified region in a region separated from a surface of said object a laser light entrance face side toward inside by a predetermined distance, along a line along which the object is intended to be cut.
5. A laser processing method according to claim 1 , wherein said leaser light comprises a pulse laser light.
6. A laser processing method according to claim 1 , wherein the irradiation of the object to be processed with laser light with a light-converging point located within the object is performed by converging the laser light emitted from a laser source and irradiating the object with the converged laser light with the light-converging point located within the object.
7. A laser processing method according to claim 1 , wherein the irradiation of the object to be processed with laser light with a light-converging point located within the object is performed by irradiating the object with the laser lights emitted from a plurality of laser sources with the light-converging point located within the object from different directions thereof.
8. A laser processing method according to claim 7 , wherein the plurality of the laser lights from the plurality of the laser source enter from a front face of the object.
9. A laser processing method according to claim 7 , wherein said plurality of laser sources comprise a laser source emitting laser light to be entered from a front face of the object and a laser source emitting laser light to be entered from a back face of the object.
10. A laser processing method according to claim 7 , wherein said plurality of the laser sources comprise light sources arranged in array along the line along which the object is intended to be cut.
11. A laser processing method according to claim 1 , wherein said modified region is formed by relatively moving the object with respect to the converging-point of the laser light located within the object.
12. A laser processing method according to claim 1 , wherein said object to be processed comprises a glass.
13. A laser processing method according to claim 1 , wherein said object to be processed comprises a piezo-electric material.
14. A laser processing method according to claim 1 , wherein said object to be processed comprises a semiconductor material.
15. A laser processing method according to claim 1 , wherein said object to be processed comprises material having a transparent characteristics with respect to the laser light with which the object is irradiated.
16. A laser processing method according to claim 1 , wherein a electronics device or electrode pattern is formed on the object.
17. A laser processing method according to claim 1 , further comprising a step of cutting the object along the line along which the object is intended to be cut after the formation of the starting point at which the object should be cut.
18. A laser processing method comprising the step of: irradiating an object made of a semiconductor material and having a wafer shape to be processed with laser light with a light-converging point located within the object to form a modified region within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a starting point, from which cutting of the object starts, constituted by the modified region in a region separated from a surface of said object a laser light entrance face side toward inside by a predetermined distance, along a line along which the object is intended to be cut.
19. A laser processing method comprising the step of: irradiating an object made of a piezoelectric material and having a wafer shape to be processed with laser light with a light-converging point located within the object to form a modified region within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a starting point, from which cutting of the object starts, constituted by the modified region in a region separated from a surface of said object a laser light entrance face side toward inside by a predetermined distance, along a line along which the object is intended to be cut.
20. A laser processing method according to claim 1 , wherein a plurality of circuits are formed on the object and the converging point of the laser light is located within the object, which faces spaces formed between the circuits adjacent to each other.
21. A laser processing method according to claim 20 , wherein the laser light is converged at angle which the plurality of the circuits are irradiated with the laser lights.
22. A laser processing method comprising the step of: irradiating an object made of a semiconductor material and having a wafer shape to be processed with laser light with a light-converging point located within the object to form a molten processed region within the object, to form a starting point, from which cutting of the object starts, constituted by the modified region, in a region separated from a surface of said object a laser light entrance face side toward inside by a predetermined distance, along a line along which the object is intended to be cut.
23. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object to form a modified region caused by multiphoton absorption within the object along a line along which the object is intended to be cut and along laser light entrance face of the object, to cut the object.
24. A laser processing method according to claim 23 , wherein the modified region is formed in a region separated from the laser light entrance face side toward inside by a predetermined distance.
25. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a modified region including a crack region within the object along a line along which the object is intended to be cut and along laser light entrance face of the object, to cut the object.
26. A laser processing method according to claim 25 , wherein the modified region is formed in a region separated from the laser light entrance face side toward inside by a predetermined distance.
27. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a modified region including a molten processed region within the object along a line along which the object is intended to be cut and along laser light entrance face of the object, to cut the object.
28. A laser processing method according to claim 27 , wherein the modified region is formed in a region separated from the laser light entrance face side toward inside by a predetermined distance.
29. A laser processing method comprising the step of: irradiating an object having a wafer shape to be processed with laser light with a light-converging point located within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a modified region including a refractive index change region which is a region with a changed refractive index within the object along a line along which the object is intended to be cut and along laser light entrance face of the object, to cut the object.
30. A laser processing method according to claim 29 , wherein the modified region is formed in a region separated from the laser light entrance face side toward inside by a predetermined distance.
31. A laser processing method comprising the step of: irradiating an object made of a semiconductor material and having a wafer shape to be processed with laser light with a light-converging point located within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a modified region within the object along a line along which the object is intended to be cut and along laser light entrance face of the object, to cut the object.
32. A laser processing method according to claim 31 , wherein the modified region is formed in a region separated from the laser light entrance face side toward inside by a predetermined distance.
33. A laser processing method comprising the step of: irradiating an object made of a piezoelectric material and having a wafer shape to be processed with laser light with a light-converging point located within the object under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width 1 μs or less, to form a modified region within the object along a line along which the object is intended to be cut and along laser light entrance face of the object, to cut the object.
34. A laser processing method according to claim 33 , wherein the modified region is formed in a region separated from the laser light entrance face side toward inside by a predetermined distance.
35. A laser processing method comprising the step of: irradiating an object made of a semiconductor material and having a wafer shape to be processed with laser light with a light-converging point located within the object, to form a molten processed region within the object along a line along which the object is intended to be cut and along laser light entrance face of the object, to cut the object.
36. A laser processing method according to claim 35 , wherein the molten processed region is formed in a region separated from the laser light entrance face side toward inside by a predetermined distance.
37. A laser processing method according to claim 22 , further comprising a step of cutting the object along the line along which the object is intended to be cut after the formation of the starting point at which the object should be cut.
38. A laser processing apparatus comprising: a laser source for emitting a pulse laser light having a pulse width 1 μs or less; a power adjustor for receiving the pulse laser light and adjusting a power of the pulse laser emitted from the laser source based on the power of the received pulse laser light; and light converging means for converging the pulse laser light so that a peak power density of the pulse laser light at the converged point reaches 1×10 8 (W/cm 2 ); adjusting means for adjusting the converging point of the pulse laser light converged by said light converging means so that the converging point is in an object; and moving means for relatively moving the converged point of the pulse laser light along a line along which the object is intended to be cut.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
March 12, 2003
January 31, 2006
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